链表相加-C语言

给定两个非空链表逆序存储的的非负整数，每个节点只存储一位数组。
请你把两个链表相加以下相同方法返回链表，保证两个数都不会以 0 开头。
数据范围：1≤n≤10⁵ ，每个节点的值都满足0≤val≤9

示例1
输入：
{2,5,6},{5,6,1}
返回值：
{7,1,8}

struct ListNode* ListAdd(struct ListNode* l1, struct ListNode* l2 ) {
    // write code here
    int sum = 0;
    int carry = 0;
    int val1 = 0;
    int val2 = 0;
    struct ListNode* lResult = NULL;
    struct ListNode* lReturn = NULL;
    struct ListNode* lTemp = NULL;
    
    while (l1 || l2 || carry == 1) {
        val1 = (l1 == NULL ? 0 : l1->val);
        val2 = (l2 == NULL ? 0 : l2->val);
        sum = val1 + val2 + carry;
        carry = sum / 10;
        sum = sum % 10;
        lTemp = (struct ListNode*)malloc(sizeof(struct ListNode));
        lTemp->next = NULL;
        lTemp->val = sum;
        if (lResult == NULL) {
            lResult = lTemp;
            lReturn = lResult;
        }
        lResult->next = lTemp;
        lResult = lResult->next;
        l1 = (l1 == NULL)? NULL : l1->next;
        l2 = (l2 == NULL)? NULL : l2->next;
    }
    
    return lReturn;
}